The present invention relates to a novel solid sweetener composition. In particular, a solid sweetener composition containing a novel aspartyl dipeptide ester compound, which has a high sweetness intensity. An example of such aspartyl dipeptide ester compounds is N-[N-[3-(3-hydroxy-4-methoxyphenyl) propyl]-L-xcex1-aspartyl]-L-phenylalanine 1-methyl ester (referred to as xe2x80x9cderivative 1xe2x80x9d).
In addition, the present invention relates to a novel liquid sweetener composition. In particular, a liquid sweetener composition of a solution, with at least one aspartyl dipeptide ester derivatives and which also contains at one of a sugar, a sugar alcohol, or an oligosaccharide as a stabilizer.
The present invention also provides a food, a beverage or other sweetened products using the same.
It has been reported that the sweetness intensity of Neotame, which is a sweetener with a high intense sweetness is 10000 times that of sucrose by weight (refer to Japanese Patent Kohyo Publication JP-A-8-503206), and the sweetness intensity of Aspartame is 200 times that of sucrose by weight (refer to Japanese Patent Kokoku Publication JP-B-47-31031). These sweeteners have been commercially and research for additional applications is ongoing. While many other sweeteners with a high intense sweetness have been proposed, these sweeteners have many practical problems for use.
Therefore, a sweetener with a high intensity sweetness, which is different from the sweetness of conventional sweeteners is in demand, preferably such a sweetener should possess a high intense sweetness, with excellent sweeteness quality, and physical properties (such as stability).
As a result of research to develop a sweet substance with a high intense sweetness, the present inventor previously found that an aspartyl dipeptide ester derivative represented by formula (2) had a high intense sweetness and was useful as a sweetener.
The present inventor has also found that the magnification of sweetness intensity of the derivative is extremely high, and that when the derivative is used directly in food, etc. in need of sweetness by sprinkling (as an example), the sweet taste is not homogeneous, which is not desired. Likewise, when a sweetener composition was prepared by mixing the aspartyl dipeptide derivative with a filler the powder form was not a homogeneous dispersion or mixture, which was not preferred due to the unbalanced sweetness.
Therefore, there is a need to develop a method whereby a sweetener composition is produced so that the composition has a homogeneous sweetness. Thus, it is an object of the present invention to develop a solid sweetener composition in which the derivative can be homogeneously dispersed and mixed.
In addition, as a result of further studies by the present inventor, the sweetness intensity of the aspartyl dipeptide ester derivative was confirmed to be extremely highxe2x80x945000 to 50000 times, or more, compared to sucrose, and attempts to prepare various types of food and beverages with the sweeteners have been undertaken. It was found that the aspartyl dipeptide ester derivative sufficiently imparted a good intensity of sweetness, sweetness quality, etc. However, several problems were still prevalent due to an intrinsic physical property of the aspartyl dipeptide ester derivative, when it is in a powder such that it was difficult to handle. For example, such a powder has a large specific volume and most of its crystals are fine and needle-like, which provides for a dangerous work environment and an ease of losing the derivative when it is spread out.
The present inventor has also found that an aqueous solution with a high intensity of sweetness was stable and useful as a liquid sweetener composition. However, it was also observed that the solubility, the dispersibility and the stability could be improved by, for example, improving the water solubility to facilitate water solubilization by preventing the formation of coagulant (the state where the powder particles are turned into a solid mass).
As the world""s population becomes increasingly focused on health, diet, etc., a non-sugar low-calorie sweetener that substitutes for sucrose is in great demand. Along these lines, there is also a need to develop ways to solve the problems that are typical of sucrose containing products, such as browning, stickiness, etc., and the suitable use of a sweetener for producing beverages, sherbets (ice block) and the like. In such production processes, various issues must be dealt with, such as, the quality of end product, the operational production efficiency, and changes in the physical property. Likewise, when prepare beverage concentrates, which will be later diluted or bottled, it is important to minimize the volume of the beverage concentrate for ease of manufacture and shipping.
Therefore, the problems that must be dealt with in this area of technology includes, among others, prevention of spreading out of the aspartyl dipeptide ester derivative; improve the solubility of the derivative for ease of dissolution; and a sweetener composition with a high intensity sweetness, which can be stored in a small place, can impart a homogeneous sweetness and be stable for a long time (high solubility and high dispersibility).
In view of the aforementioned problems, a stable sweetener composition with a high intensity sweetness containing the aspartyl dipeptide ester derivative and which can be handled easily without spreading out has been in demand.
Accordingly, one object of the present invention is to develop a solid sweetener composition in which the aspartyl dipeptide ester derivative can be homogeneously dispersed and mixed.
Another object of the present invention is to provide and obtain a liquid sweetener composition which is high in quality and facilitates process control and operational efficiency during the production and delivery.
The present inventor has found that a solid sweetener composition containing at least the aspartyl dipeptide derivative and a solid filler can be obtained by a process whereby the derivative is mixed in a solution during manufacture whereby the derivative is mixed and dispersed homogeneously.
One embodiment of the present invention is a solid sweetener composition containing an aspartyl dipeptide ester derivative or a salt thereof, represented by formula (2), including formula (1); and a solid filler, whereby the composition can be produced by mixing the derivative in a solution during manufacture, whereby the derivative is mixed and dispersed homogeneously.
The sweetness intensity of the aspartyl dipeptide ester derivative in the sweetener composition is preferably more than 4,000 times that of sucrose.
The aspartyl dipeptide ester derivative in the solid sweetener composition includes salts thereof, one compound alone or mixtures thereof.
The compounds of formulas (1) and (2) are: 
where R1, R2, R3, R4 and R5 are independently a hydrogen atom, a hydroxyl group, an alkoxy group having 1 to 3 carbon atoms (methoxy, ethoxy, n-propoxy, etc.), an alkyl group having 1 to 3 carbon atoms (methyl, ethyl, n-propyl, etc.) and a hydroxyalkyloxy group having 2 or 3 carbon atoms (O(CH2)2OH, OCH2CH(OH)CH3, etc.), and where R1 and R2, or R2 and R3 may be combined together to form a methylene dioxy group (OCH2O); where R6, R7, R8, R9 and R10 are independently a hydrogen atom or an alkyl group having 1 to 3 carbon atoms (a methyl, an ethyl, an isopropyl group, etc.) and any two of R6, R7, R8, R9 and R10, may be combined together to form an alkylene group having 1 to 5 carbon atoms (CH2, CH2CH2, CH2CH2CH2, etc.); when R6 and R7, or R8 and R9 are different substituents, or R10 is a substituent except for a hydrogen atom, the configuration of the carbon atom to which R6 and R7, R8 and R9 or R10 are linked, has no restriction, and may be any one of (R), (S) and (RS) or mixture thereof. The wiggly lines depicted as the bond of R6 to R10, and a hydrogen atom with a carbon atom in formula (2) means that the direction of the bond is free (is not specified).
However, where R6 is a hydrogen atom or a methyl group and R1, R2, R3, R4, R5, R7, R8, R9 and R10 are hydrogen atoms is excluded from the present invention. In addition, the derivative where R2 or R4 is a methoxy group, R3 is a hydroxyl group, R10 is a hydrogen atom or a methyl group, and R1, R4, R5, R6, R7, R8, and R9 are hydrogen atoms is excluded.
The aspartyl dipeptide ester derivative used for the solid sweetener composition is preferably one where R8, R9 and R10 are hydrogens. Various embodiments of the aspartyl dipeptide derivative are those compounds where: (1) R3 is a hydroxyl group or a methoxy group, and R4 and R5 are hydrogens; (2) where R1 is a hydroxyl group; (3) where R1 is a hydrogen atom; (4) where R2, R6 and R7 are hydrogens; and (5) where R2 is hydrogen, a hydroxyl group or a methyl group.
Another preferred set of aspartyl dipeptide ester derivatives of the present invention are listed in the following Table 1, where all of R8, R9 and R10 are hydrogens:
The salts of the aspartyl dipeptide ester derivatives described above include, for example, edible salts (such as hydrochloride salts), sodium salts, potassium salts, ammonium salts, calcium salts and magnesium salts, etc.
To manufacture the aspartyl dipeptide ester derivatives of the present invention Aspartame is reductively alkylated with 3-phenylpropionaldehyde derivative, cinnamaldehyde derivative or (2-phenylethyl) alkyl ketone derivative having various substituents on the phenyl group and one or two alkyl substituents on the main chain, and a reducing agent (e.g., hydrogen/palladium carbon catalyst). Alternatively, the derivative compounds can be obtained by reductively alkylating the Aspartame derivative, which has a protecting group for the carboxyl group at the xcex2 position (for example, xcex2-o-benzyl-xcex1-L-aspartyl-L-amino acid methyl ester), which can be obtained by ordinary peptide synthesis method (Izumiya et al., Fundamentals and experiments of peptide synthesis: Maruzen, published on 1985.1.20) with the 3-phenylpropionaldehyde derivative, cinnamaldehyde derivative or (2-phenylethyl) alkyl ketone derivative described above, and a reducing agent (e.g., NaB(OAc)3H) (A. F. Abdel-Magid et al., Tetrahedron Letters, 31, 5595 (1990)), and then removing the protecting group, or by saturating the unsaturated bond with a reducing agent, if needed. An acetal or ketal derivative thereof or so on can also be used as an aldehyde or ketone component for the reductive alkylation 3-phenylpropionaldehyde derivative, cinnamaldehyde derivative or (2-phenylethyl) alkyl ketone derivative.
These derivative can be easily produced by known peptide synthesis method, or according to the production examples of derivatives 1 to 9 as described below.
The sweetening composition can include one or more aspartyl dipeptide ester compounds and/or mixed with one or more additional sweetening ingredients. The sweetener composition can also have one or more fillers. Such fillers are those ingredients that adjust the sweetness of the derivatives and include, but not limited to, sugars, sugar alcohols, oligosaccharides, polysaccharides, etc. The sweetener composition may also contain one or more bulking agents, carriers, etc. The fillers can be included in an amount so long as it does not inhibit the the object of the present invention.
The sugars include, but are not limited to, sucrose compounds, invert sugar, isomerized sugar, glucose, fructose, lactose, malt sugar, D-xylose and isomerized lactose. The sugar alcohol include, but are not limited to, maltitol (including reduced malt sugar syrup, etc.), sorbitol, mannitol, erythritol, xylitol, lactitol (including reduced lactose, etc.), paratinit, and reduced starch sugar (including hydrogenated starch syrup, etc.). The oligosaccharides include, but are not limited to, fructooligosaccharide (including neosugar, etc.), maltooligosaccharide (including linear oligosugar, etc.), isomalto-oligosaccharide (including branched oligosugar, etc.), galactooligosaccharide, soy been oligosaccharide and lactooligosaccharide, and further the polysaccharide comprises glucomannan, dietary fiber (including enzyme decomposition products of guar gum such as galactomannan Hydrolysate, etc.), non-digestible dextrin (dextrin including dietary fiber), polydextrose and starch (including dextrin, soluble starch, modified starch, etc.), etc. The fillers can be used singly or in combination.
The sucrose compounds referred to above, include, but are not limited to sugar bound syrup (including coupling sugar, glucosylsucrose, etc.), paratinose (including isomaltulose, etc.), trehalose, etc.
To make the solid sweetener composition the derivative is mixed in a solution, whereby it is preferred to completely dissolve the derivative, homogeneously, and/or an intermediate state thereof, e.g., partial dissolution and remaining partial dispersion. In another preferred embodiment, the solid sweetener composition can be obtained by homogeneously mixing the composition in a solution, and drying the solution as needed. The solvent for dissolving the aspartyl dipeptide ester compound can be any solvent, which can be used for drinking and eating and which dissolves the derivative. Such solvents include, but are not limited to water, alcohols (e.g., ethanol), polyvinyl acetate, oils and fats, etc. Methods for homogeneous mixing in a liquid solution and drying used herein are known in the art.
In another embodiment, a filler is included during the dissolving process
The solid sweetener composition containing the aspartyl dipeptide ester compound can be used as a tabletop sweetener or other type of sweetener, or in various edible products. Examples of such edible products include, but not limited to, powdered juice, powdered cocoa, powdered cola, instant coffee, black tea and so on, chocolate, chewing gum, health food, medicine, etc.
The food or beverage (e.g., a cola beverage) that is obtained using the solid sweetener composition can be used to make further products, such as a juice that can be obtained by dissolving the powdered juice in water, bread, cakes, chocolate or as a topping on such products like yogurt.
Another embodiment of the present invention is a stable liquid sweetener composition that contains the aspartyl dipeptide ester derivative with a high intensity sweetness in an edible medium, such as water, alcohol and the like. This liquid composition can be a suspension in which the aspartyl dipeptide ester derivative has been stably dissolved and stably dispersed.
The sweetness intensity of the aspartyl dipeptide ester derivative used for the liquid sweetener composition of the present invention is preferably more than 4,000 times that of sucrose.
The edible medium (water, alcohol, etc.) can include a stabilizer (bulking agent), a thickening agent, a filler, etc. These are preferably used as a medium for suspension.
At least one of the compounds contained in the group consisting of sugar, sugar alcohol, and oligosaccharide can be added as a stabilizer. As a result, a suspension having a high solubility, a high dispersibility and a high stability in terms of the derivative can be prepared.
As described above, the liquid medium is preferably water, alcohol, and a mixed solvent containing any one of water and alcohol and the like as the edible medium, also the stabilizer as described above may be included. A liquid solution can be prepared in the form of suspension, preferably a homogeneous suspension, which contains at least one of the aspartyl dipeptide ester derivatives in a high concentration than that in the solubility in the liquid medium.
The sweetener composition in the form of stable suspension can be obtained by mixing at least one of the aspartyl dipeptide ester derivatives in a higher concentration than that of the solubility of the derivative in the liquid medium. The mixing method is preferably the vacuum mixing method.
The liquid sweetener composition can be in the form of a sweetener, food, beverage, a frozen dessert, a syrup, a pharmaceutical product (medicine), oral cosmetics, such as toothpastes, among others.
There is no particular restriction to the mixing ratio of aspartyl dipeptide ester derivatives and the solid filler used in the solid sweetener composition. Preferably, the aspartyl dipeptide ester derivatives are in the amount of about 2 ppm (by weight) to about 95% (by weight) relative to the total amount of the composition, preferably in an amount of about 0.2 ppm (by weight) about to 95% (by weight).
When the solid sweetener composition is prepared, the aspartyl dipeptide ester derivative is mixed with at least with the component(s) for the composition including the filler, in a solution homogeneously.
Furthermore, the sweetener can be mixed with another sweetener ingredient(s) (another sweetener with a high intensity sweetness such as Aspartame, and the third and fourth sweetener ingredients such as sugar, sugar alcohol and the like). The compositions can also include other ingredients other than sweeteners, such as salts, e.g., sodium chloride.
When the solid sweetener composition in the present invention is used for a sweetener, various known carriers, bulking agents, etc. can be included in the composition as necessary other than the filler.
The solid sweetener composition of the present invention comprises a sweet substance and a filler, such as a sweetener, and a food comprising a sweet substance and a filler such as a fondant-like food. Moreover, the food composition can be obtained by mixing various ingredients necessary for the food other than the filler, the sweetener ingredient, etc. Ingredients imparting fruit tastes for powdered juices, flavor ingredients necessary for candy and jelly, an ingredient for tablet candy (where the outer portion is prepared separately), nutritious ingredients for nutritional supplements, pharmaceutical active ingredient(s) for pharmaceutical products, coffee ingredients for powdered coffee, dairy ingredients for powdered dairy products, dentifrice ingredients for tooth paste and tooth powder, etc. can be included in the foods as desired.
Other embodiments of the invention include, but not limited to, a tabletop sweetener composition (coating the surface of the fine crystals in powder filler), powdered cocoa, powdered cola, powdered coffee (spray dried product), instant coffee, health care foods (freeze dried product) and powdered juices (concentrated dried product), other powdered food product, granular medicine-type products, powdered flavor seasoning as a granulated product, chocolate, chewing gum, and fondant-like food.
There are no particular difficulties for producing the product in the present invention (e.g., the solid sweetener composition), and can include a mixed dispersion method using a solvent. For example, the products can be prepared as follows.
1. The composition can be produced by drying a solution of the composition in which the composition ingredients are dissolved homogeneously.
2. The composition can be included: solidifying by a method of condensation drying for Aspartame-containing sugar (refer to Japanese Patent Kokai Publication JP-A-63-146768, etc.), spray drying for the composition for imparting sweetness (refer to Japanese Patent Kokai Publication JP-A-58-20588, etc/), freeze drying for instant coffee (refer to Japanese Patent Kokai Publication JP-A-59-45849, etc.), extrusion granulation for low-calorie sweetener (refer to Japanese Patent Kokai Publication JP-A-1-206969, etc.), and absorption to form solid sweeteners (refer to Japanese Patent Kokai Publication JP-A-58-36368, etc.).
A suitable solvent to be used, include but are not limited to, any one of water, alcohol such as ethanol, and a homogeneously mixed solvent comprising at least any one of the both, is preferable.
3. The solution of the aspartyl dipeptide ester derivative(s) is coated on the surface of the filler homogeneously, for example, as described for the production of a composition containing Erythritol (refer to Japanese Patent Kokai Publication JP-A-4-335870, etc.).
4. The solvent in the solution, e.g., water, alcohol such as ethanol or a mixed solvent of the two, can be spread by spraying on the surface of the fine crystals of the powder as described, for example in Japanese Patent Kokai Publication JP-A-1-95741, etc.
Other uses of the solid sweetener composition in food and beverages, which are in need of a sweet taste include, for example, a fruit juice beverage, cola beverage, a frozen dessert, an ice cream, an ice lolly, a bread, a cake and so on, a sanitary product, cosmetics (including a oral composition such a tooth paste and powder), a medicine, a product for an animal other than human, etc.
The solid sweetener is homogeneously dispersed or mixed with the components of the food and beverage, for example, in making a juice the solid sweetener is dissolved in the water that will serve as the dissolving medium for a powdered juice product.
In another embodiment of the present invention, a liquid sweetener composition is provided. Such liquid sweetener compositions contain the aspartyl dipeptide ester derivatives represented by formula (2), particularly general formula (1), and more particularly the aforementioned 9 derivatives (referred to as xe2x80x9cderivative 1xe2x80x9d to xe2x80x9cderivative 9xe2x80x9d). While the liquid sweetener composition is explained primarily on these derivatives, the liquid sweetener composition of the present invention is not limited to the use of these derivatives.
These aspartyl dipeptide ester derivatives are prepared as described above.
The liquid sweetener composition of the present invention can include as a stabilizer a sugar, a sugar alcohol, an oligosaccharide, and mixtures therof, which are described above. Preferred for use in the liquid sweetener composition are isomerized sugar, sugar alcohol (such as sorbitol), hydrogenated starch hydrolysate and coupling sugar.
The liquid sweetener compositions of the present invention have a high intensity sweetness, which can be enriched by the addition of the sugar and the like, which can be provided at the same time as the aspartyl dipeptide ester derivatives and thereby yielding a stable liquid system. The crystals of the derivatives can be dispersed homogeneously in a liquid solution. The liquid sweetening composition of the present invention can be used for imparting sweetness in a food and/or beverage, which provides a highly practical sweetener for the raw material of beverage, desert, frozen dessert and similar products.
The aspartyl dipeptide ester derivatives generally have a low solubility in water (1 to 1000 mg/100 ml), however, the low solubility provides an intense sweetness in products containing the same. These compositions can also be a suspension containing the aspartyl dipeptide derivatives in a concentration higher than their solubility in the medium. When the viscosity of the suspension medium is low, a heterogeneous sediment may be observed, however, the sediment can be dispersed homogeneously by agitation. To keep the suspension homogeneous, it is preferable to select and use a suspension medium that has a viscosity which can maintain the stability of the suspension. For example, a solution containing a sugar can be used as a stabilizer in the edible medium (such as water), or a gum substance such as xanthan gum, guar gum, a viscosity-improving stabilizer such as a polysaccharide and a specific gravity-increasing component can be included in the compositions of the present invention. The composition can also contain components to improve solubility and dispersibility, for example viscosity-improvers, fillers or surface-active agents.
The stabilizer can be a single stabilizer or mixture of two or more stablizers thereof.
The amount of the aspartyl dipeptide ester derivative(s) in a suspension medium is preferably in an amount such that at least one part of the derivative can be maintained stably in the insoluble state. The lower limit of the amount of the aspartyl dipeptide ester derivative to produce the suspension, is an amount sufficient for providing a super saturated suspension while stored at room temperature. The upper limit of the aspartyl dipeptide ester derivative is to obtain the target intensity of sweetness. When the amount of the aspartyl dipeptide ester derivative required for the target sweetness intensity is less than the saturation amount, the solution can be used as a liquid sweetener composition.
The liquid compositions can also contain other seasoning ingredient(s) including, but not limited to sodium L-glutamate, tasty (gustatory) substances (e.g., 5xe2x80x2-nucleotide), sweetening substance (e.g., steviosides and saccharine), organic acid, amino acid, peptides, extracts, flavors, spices, colorants, inorganic substances like calcium and magnesium, vitamins, and lipids. The liquid sweetening composition can also contain salts, such as sodium chloride. When fats and oils are used at the same time, they can be provided as an emulsion, preferably a o/w or w/o type emulsion.
The liquid sweetener composition of the present invention can be produced by, for example, mixing one or more of the aspartyl dipeptide ester derivatives in a liquid medium to form a solution or slurry like suspension. The mixing can be also include heating and cooling the mixture as appropriate. The liquid sweetener composition can be prepared as follows:
The mixture of the aspartyl dipeptide ester derivative(s) and water, which can also include a stabilizer whereby the stabilizer and the derivatives(s) are added at the same time, or in subsequent mixing steps. Preferably, the mixture is at some point in the mixing process, preferably throughout the entire mixing process, performed under vacuum to prevent air bubbles.
The liquid sweetener composition can be in a variety of forms including, but not limited to a homogeneous solution, homogeneous dispersed solution, a paste, a fluid or semi-fluid of soft or hard cream-like. For example, paste-like forms, or cream-like forms are more suitable for mixing with viscous materials in a process for producing an edible product, such as a frozen dessert.
The liquid sweetener compositions of the present invention are highly stable during storage with respect to the aspartyl dipeptide ester derivative(s) whereby the aspartyl dipeptide ester derivative(s) do not decompose and remain soluble in solution for long periods of time yielding a product that is without loss of sweetness. In addition, because the stabilizer makes it possible to improve the dispersibility and solubility in water compared with the aspartyl dipeptide ester derivative alone, the sweetener composition can be used in a variety of food products or food service uses, such as beverages, sherbets, syrups and venders.
The liquid sweetener composition of the present invention can be produced as a sweetener, or directly into a form of a food or beverage, such as a frozen dessert. The liquid sweetener composition of the present invention can be used as a sweetener for various edible products including but not limited to a confectionery (a frozen dessert, a jelly, a cake, a candy), bread, chewing gum, a sanitary product, cosmetics (including an oral composition such a tooth paste and powder), a medicine and a product for an animal other than human, which are in need of an imparted sweet taste. In addition, the liquid sweetening compositions of the present invention can be used in a way that sweeteners are commonly used.
The following Examples provide an illustration of embodiments of the invention and should not be construed to limit the scope of the invention, which is set forth in the appended claims.